But that URL won’t work unless you’re staff because its pagination counts whispers, and if you’re not staff, there is no page 4.
(If the above topic gets enough new replies by the time you see this that it starts working, try the permalink to the latest reply, the bug should still be present.)
I bumped into this bug when consuming the Discourse RSS feed with Feedly. Feedly crawls links and replaces the <link> element with the canonical URL listed in the source. So, in practice, when I clicked on this post in the RSS feed, I hit an error page.